JP3590099B2 - Method and apparatus for automatically detecting the position of a start hole and automatically inserting a wire electrode into the start hole in wire electric discharge machining - Google Patents

Description

[0001]
[Industrial applications]
INDUSTRIAL APPLICABILITY The present invention is applied to a method and an apparatus for wire electric discharge machining, in particular, when machining is started or when machining is restarted after disconnection of a wire electrode, a wire electrode is inserted into a machining start hole by automatic control and machining is started. The present invention relates to an automatic start hole searching method, that is, a method of detecting a position, a method of automatically inserting a wire electrode into a start hole, and an apparatus therefor.
[0002]
[Prior art]
In recent years, wire electric discharge machines have become highly automated, and the insertion of a wire electrode into a machining start hole of a workpiece set on a work stand and the stretching of a wire electrode traveling system, etc. are automated in various methods and modes. ing.
[0003]
However, insertion of the wire electrode into the processing start hole of the workpiece is not easy regardless of the insertion method, including the case of insertion after a wire electrode disconnection accident. For example, the workpiece having the start hole opposed to the tip of the wire electrode in the vertical direction is relatively moved and positioned by the NC control in a direction perpendicular to the facing direction, and then the tip of the wire electrode is sent out. Is to be inserted. Regardless of the wire electrode sending method and mechanism, in particular, depending on the positioning guide on the wire electrode sending side, the power supply, the treatment of the nozzle and its injection port, etc., the habit of the wire electrode, the remaining situation such as distortion, etc. There is a case where the target insertion set cannot be performed by one insertion operation, and the processing is stopped at that point.
[0004]
Therefore, when the setting operation fails due to the automatic insertion of the wire electrode, the setting operation is detected and determined by some means, and a desired portion from the tip of the wire electrode sent out for insertion based on the detection signal is determined. Rewinding, cutting or sending out a part or most of the part that has been cut or sent out by a cutting device, and after removing the cut part of the wire electrode, re-entering the process of automatic insertion operation of the wire electrode again (See, for example, Japanese Patent Application Laid-Open No. 58-177,234).
[0005]
However, in the case of a thin wire electrode having a diameter of the wire electrode of about 0.1 mmφ or less, for example, about 0.05 mmφ or about 0.03 mmφ, the wire electrode has a low rigidity, so that the wire electrode cannot be inserted or fed forward. It is buckled or deviated from the passage to be inserted due to slight contact failure or disturbance, and cannot be inserted. Also, not only does the diameter of the start hole tend to be reduced in accordance with the diameter of the wire electrode, but also the diameter of the start hole tends to be reduced relative to the diameter of the wire electrode. Making it difficult.
[0006]
In addition, the start hole at the start of processing may not only have to be reduced due to the relationship between the workpiece material and the dimensions and shape of the processing, etc., but also need to be mechanically drilled or the like before quenching the workpiece. In the case of forming, when performing wire electric discharge machining after quenching the work piece, the size, shape, position, etc. of the work piece and the start hole are slightly changed from those in the manufacturing drawings etc. due to distortion etc. Often. Therefore, there are many cases where the purpose of the insertion set cannot be achieved by simply repeating the automatic insertion operation of the wire electrode as described above.
[0007]
For this reason, when the wire electrode is sent out for automatic insertion, the insertion is not performed due to the relative displacement of the start hole, or when the contact between the wire electrode and the workpiece is detected, the wire electrode is After cutting or further stopping the feeding of the wire electrode, the wire electrode and the workpiece are moved relative to each other in a direction perpendicular to the facing direction according to a predetermined setting pattern or distance to set the start hole position. After detecting and correcting the positional displacement amount such as contact cancellation, a method of attempting an automatic insertion operation of the wire electrode such as sending out the wire electrode (Japanese Patent Application Laid-Open Nos. 56-119, 327 and 1-135,423). And Japanese Patent Application Laid-Open Nos. 2-3111 and 221) to search for a start hole. Alternatively, as described in JP-A-5-253749, for example, Place A start hole position identification means of a light emitting means and a light receiving means is provided in a head of a wire processing machine, and the identification means is relatively scanned and detected at a position close to the start hole to determine a start hole center position coordinate. It has been proposed to accurately position the center of the wire electrode insertion hole in the head of the wire electric discharge machine at the center position of the start hole.
[0008]
[Problems to be solved by the invention]
However, in the former case, the tip portion of the wire electrode sent out from the wire electrode guide (pipe) for insertion of the start hole is always in the correct position with respect to the electrode guide, that is, the wire electrode is processed. The fact that the wire is not inserted into the start hole due to contact or contact with the body is based on the premise that the position of the wire electrode guide is shifted from the position of the start hole. Various misalignments of the electrode, bending near the tip, dirt around the entrance of the start hole or its surroundings, and the presence of machining fluid or other foreign matter are often the cause. Even if the correction of the positional deviation between the start hole and the wire electrode guide is performed, it is not always possible to insert the wire electrode, and it is often necessary to repeatedly search for the start hole. It was unsatisfactory. Further, when the position of the start hole is largely shifted, it is difficult to search for the start hole with the wire electrode over a wide range. In addition, the latter method of using the light emitting / receiving means with the start hole identification means is not only a problem that the sensor must be provided on both sides of the workpiece, but also the center position of the wire electrode insertion hole and the identification optical axis. In addition to the problem of misalignment of the start hole and the problem of alignment in the case of a separate body, the start hole or the vicinity of the start hole is vulnerable to dirt and foreign matter, and the thickness of the workpiece plate increases and the formation start hole It was difficult to respond to bending and thinning. In addition, in the conventional method and apparatus for searching for a start hole as described above, for example, a small and many start holes of a synthetic fiber nozzle working workpiece having a large number of irregularly shaped holes of about 0.03 to 0.1 mmφ are provided. For this reason, it has been difficult to measure the position of each hole after drilling and to cope with a workpiece whose measurement record has not been recorded. In addition, measuring the start holes and inputting the positions of the start holes as position data into the program requires a great deal of labor.
[0009]
Accordingly, an object of the present invention is to provide a wire in which the insertion of the wire electrode into the processing start hole of the workpiece set on the conventional work stand and the mounting of the wire electrode such as the stretching to the wire electrode traveling system are automated. By improving the start hole search function of the electric discharge machine and its accuracy, and by using the wire electrode insertion mechanism and the like already provided in the wire electric discharge machine, the additional component parts and the like can be reduced as much as possible. By devising a configuration that can be performed, accurate and quick search and position detection of the start hole can be performed, and as a result, the automatic insertion set of the wire electrode can be performed with high probability, quickly and without a complicated and expensive configuration. It is to be.
[0010]
[Means for Solving the Problems]
The above-mentioned object of the present invention is as follows: (1) The machining liquid jet nozzle provided in the upper machining head is also used. There is A processing fluid injection pipe facing vertically below the workpiece to be processed, and forming at least one processing start hole formed in a desired position of the workpiece in advance in a direction perpendicular to the facing direction. To search by relative feed of control command,
A step of starting the injection of the machining fluid by bringing the machining fluid injection pipe close to a predetermined state on the upper surface of the workpiece and starting the measurement of the pressure or the flow rate of the machining fluid in the injection pipe or a flow path connected thereto; When,
Scanning the working fluid injection pipe relative to the workpiece in a predetermined area in a direction perpendicular to the facing direction relative to the workpiece by a preset scanning program in a predetermined order,
A step of measuring and storing relational data of a relative position by scanning of the relative movement with respect to a change in pressure or flow rate of the working fluid in the working fluid injection pipe or a flow path connected thereto,
Calculate based on the stored data of the relationship between the change in the pressure or flow rate of the machining fluid in the machining fluid injection pipe or the flow path connected thereto and the relative position between the machining fluid injection pipe and the workpiece and the machining fluid injection pipe. Determining the position of the start hole in the wire electric discharge machining having a step of determining a relative position with respect to the start hole,
[0011]
Also, (2) the machining liquid jet nozzle provided on the upper machining head is also used. There is A wire electrode is inserted through a working fluid injection pipe, and the working fluid injection pipe is opposed to a workpiece disposed vertically below, and one or more workpieces formed in advance at desired positions on the workpiece. After positioning by a relative feed of a numerical control command in the direction perpendicular to the facing direction with the machining start hole, the wire electrode is sent out from the machining fluid injection pipe and inserted into the start hole, or 1 to the start hole. At the time of re-insertion operation after detecting failure of wire electrode insertion operation more than once,
The working fluid injection pipe is brought close to a predetermined state on the upper surface of the workpiece to start injection of the working fluid, and the inside of the working fluid injection pipe starts measuring the pressure or flow rate of the working fluid in the flow path connected to the pipe. To do,
Scanning the working fluid injection pipe relative to the workpiece in a predetermined area in a direction perpendicular to the facing direction relative to the workpiece by a preset scanning program in a predetermined order,
A step of measuring and storing relational data of a relative position by scanning of the relative movement with respect to a change in pressure or flow rate of the working fluid in the working fluid injection pipe or a flow path connected thereto,
Calculate based on the stored data of the relationship between the change in the pressure or flow rate of the machining fluid in the machining fluid injection pipe or the flow path connected thereto and the relative position between the machining fluid injection pipe and the workpiece and the machining fluid injection pipe. Determining the position of the start hole in the wire electric discharge machining having a step of determining a relative position with respect to the start hole,
[0012]
(3) The relative scanning movement of the workpiece (1) or (2) in the direction perpendicular to the facing direction and the direction perpendicular to the facing direction according to the set scanning program between the workpiece and the working fluid injection pipe, and Or, the data that measures and stores the pressure or flow rate of the machining fluid in the flow path connected to it in relation to the relative position by scanning the relative movement, and the relative position between the machining fluid injection pipe and the start hole that is calculated based on the stored data Is determined following each of the following steps (a) to (f),
(A) executing the scanning as a reciprocating scan at a predetermined pitch in one axis direction and a predetermined set distance in the other axis direction perpendicular to the one axis direction;
(B) A scanning path in which the machining fluid injection pipe and the start hole overlap by a predetermined ratio or more by the scanning movement. On the road Storing the position of the predetermined value at which the pipe port and the hole port overlap and start increasing by a predetermined value or more as the first or direct position data by a change in the measured value of the pressure or flow rate of the working fluid. ,
(C) By the scanning movement after the step (b), the overlap between the pipe port and the hole starts to decrease, and the overlap position equivalent to the first position is a measured value of the pressure or flow rate of the working fluid. Storing as a direct or indirect second position data by the change;
(D) calculating and calculating an intermediate position between the scanning paths at both positions from the stored data at the first position and the second position;
(E) switching to the scanning movement in the one axis direction perpendicular to the scanning movement axis according to the coordinates of the intermediate position on the scanning movement axis, and starting the scanning movement;
(F) In the scanning movement in the one axis direction, the steps (b), (c), and (d) in the scanning movement in the other axis are sequentially executed to determine the center position of the start hole. Seeking stage.
[0013]
(4) As an apparatus for performing the method of (1), (2) or (3),
The work fluid jet nozzle provided on the upper work head held by the machine so that it can approach and separate from the work piece installed on the work table from above can be shared. There is Machining fluid injection pipe,
Work the machining liquid injection tube On the body A machining fluid supply device that ejects machining fluid from an ejection pipe in a state where the machining fluid is positioned close to the surface,
A device for measuring the pressure or flow rate of the machining fluid in the portion provided in the machining fluid injection pipe or the machining fluid supply conduit connected to the same,
A scanning program storage device storing a scanning program for relatively moving the working fluid injection tube at the close position in a direction perpendicular to the direction facing the workpiece, and a storage scan of the scanning program storage device A relative movement scanning device between the machining fluid injection tube and the workpiece to execute a program under control by a numerical controller,
Execution of the scanning program by the moving scanning device at the time of moving scanning, a storage device for sequentially storing relational data of the coordinate position of the moving scan with respect to the measurement value of the pressure or flow rate measuring device of the working fluid,
After the end of the predetermined moving scan by the moving scanning device, the stored data of the relationship between the pressure or flow rate of the measured working fluid and the relative position between the working fluid ejection tube and the workpiece is read out from the storage device, and the machining fluid ejection tube is read. A calculation program storage device for calculating and determining the relative position with respect to the machining start hole,
A configuration comprising a control device having a numerical control device for controlling the operation of the working fluid supply device, the working fluid pressure or flow rate measuring device, the moving scanning device, the respective storage devices for scanning programs and data, and the operation program storage device; Can be achieved.
[0014]
The object of the present invention for automatically inserting a wire electrode is to perform the wire electrode insertion operation after detecting the position of the start hole in the means (1), (2) and (3) for solving the above-mentioned problems. At the time of the operation of detecting the position of the start hole, first, the tip of the wire electrode is set in a predetermined insertion state from the rear end of the machining liquid injection pipe so that the transition of the start hole can be performed immediately. At the rear, the wire electrode is gripped and clamped, and when the position of the start hole has been detected by means of (1), (2) and (3), the newly determined relative position is first determined. Relative feed in the direction perpendicular to the facing direction is performed in accordance with the position data to perform relative positioning between the machining liquid ejection tube and the start hole, and then release the grip of the wire electrode and supply the machining fluid ejection tube to the machining liquid ejection tube. The coating liquid pressure not so that the insertion operation of the wire electrode is performed by increasing the one in which rapid reliable insertion purposes is achieved.
[0015]
Furthermore, the position of the start hole provided in the workpiece is Prior to processing In the search method of the start hole to search,
Provided on the upper processing head A step of facing a measuring member for injecting the working fluid at a predetermined distance to the upper surface of the workpiece,
While spraying the machining fluid from the measuring unit, the upper surface of the workpiece is Relatively horizontal Scanning movement to;
Detecting a change in pressure (or flow rate) of the processing liquid supplied to the measurement member during the scanning movement in relation to a scanning position;
The object of the present invention can be achieved by a method for detecting the position of a start hole in wire electric discharge machining, which comprises the step of calculating scanning position data upon detecting a change in pressure (or flow rate).
[0016]
[Action]
According to the above-described method for detecting the position of the start hole, a machining liquid ejection nozzle that ejects a machining fluid to a machining portion during machining, which is normally provided in such a device, or that the machining fluid ejection nozzle also serves as There is In order to automatically insert the wire electrode through the machining fluid jet tube, guide the wire electrode as necessary, and use the machining fluid jet jet tube that sends the wire electrode to the start hole and lower guide as it is. Since the presence and the position of the start hole are detected, a means for detecting a change in the pressure or flow rate (or flow velocity) of the working fluid and outputting a signal, or a working fluid injection pipe and a workpiece according to the detection signal It is necessary to store and calculate data related to the relative position between the start holes, but most of these can be handled by expanding the functions of existing equipment and devices. Therefore, it is possible to reliably detect and position the position of the start hole without causing congestion of various devices in the processing head portion or increasing the price.
[0017]
Further, according to the above-mentioned automatic insertion method of the wire electrode, according to the detection position data after the detection of the position of the start hole, after the update positioning of the machining liquid injection tube and the start hole, or when necessary, the machining liquid injection tube is The wire electrode is advanced forward with the wire electrode, and simultaneously with the ejection of the machining fluid jet that automatically inserts the wire electrode, the gripping clamp on the wire electrode that prevented the wire electrode from moving forward and backward is simply released, and the automatic insertion of the wire electrode immediately starts. Since the probability of the automatic insertion and setting of the wire electrode is high, the operation can be easily and repeatedly performed together with the operation for detecting the position of the start hole, and the degree of achievement of the object can be enhanced.
[0018]
【Example】
1 and 2, FIG. 1 is an explanatory view showing a schematic configuration of an entire apparatus for performing the method of the present invention, FIG. 2 is a front explanatory view showing a partial configuration of a main part, 1 is a wire electrode, 2, 3 Are upper and lower working fluid nozzle blocks, and the upper working fluid nozzle block 2 is attached to a column 5 erected on a base bed 4 and an upper arm 6 attached to the column 5 in the vertical Z-axis direction so as to be freely positioned. The nozzle block 3 is attached to the pointed end of the processing head 7, and the nozzle block 3 is disposed at the pointed end of the lower arm 8 fixedly attached to the column 5 so as to face the upper nozzle block 2 vertically uniaxially. The wire electrode 1 is renewed and fed from above to below in the axial direction with a predetermined tension applied between the upper and lower positioning guides between the upper and lower working fluid nozzle blocks 2 and 3 (not shown). Reference numeral 9 denotes an XY cross table, which is arranged on the bed 4 and is orthogonal to the axis of the wire electrode, on which a work stand 10 is mounted, and a workpiece 11 is attached to the work stand 10 and a wire electrode between the upper and lower guides is provided. 1 and are opposed to each other from a direction substantially perpendicular to the axial direction. Reference numeral 12 denotes a Z-axis drive motor for feeding and positioning the processing head 7 in the Z-axis direction along the guide 5A of the column 5, 12A denotes an encoder for detecting the rotation angle of the motor 12 and the Z-axis position of the processing head 7, and 13 and 14 The X-axis and Y-axis drive motors of the XY cross table, 13A and 14A are encoders for detecting the respective axes, and set the proximity or the separation position of the processing head 7 and the upper processing liquid nozzle block 2 with respect to the surface of the workpiece 11. At the same time, the shape machining feed and feed movement are performed in accordance with a machining program command in a direction perpendicular to the machining portion wire electrode 1 between the upper and lower machining fluid nozzle blocks 2 and 3 (horizontal direction) and other setting program commands. In FIG. 1, a UV axis table normally provided so as to attach the upper nozzle block 2 to the processing head 7 and a drive thereof for so-called taper processing for performing processing by inclining the wire electrode because they are not directly related to the present invention. Parts are omitted.
[0019]
The wire electrode 1 is sent out or pulled out from a wire electrode supply bobbin 15 provided in the column 5, and is pressed by a pinch roller 19 via a guide roller 16 and a guide 17 against a tension roller 18 connected to a powder brake or the like. It can be applied, and the direction is changed to the processing portion by the upper direction conversion pulley 20, and passes through the processing start hole 11 A of the workpiece 11 via the wire electrode automatic insertion mechanism 21 of the processing head 7 and the upper processing liquid nozzle block 2. To the lower working fluid nozzle block 3, passing from the lower direction conversion pulley 22 through a guide pipe 23 provided along the lower arm 8, a suction device 24 as a lower wire electrode pulling device, and a pair of wire electrode sandwiching wire feed rollers 25, the wire electrode collection box 2 from the wire electrode discharge portion 26 while applying the tension. It is to a feed recovery. Reference numeral 28 denotes a supply wire electrode cleaning roller provided on the wire electrode supply side, and reference numeral 29 denotes a disconnection detector.
[0020]
Numeral 30 denotes a working fluid circulation / supply device, which has a clean working fluid tank 30A and a dirty working fluid tank 30B. The processing liquid in the liquid tank 30B is pumped up by a pump 31 via a sedimentation section (not shown), filtered by a filter 32, sent to a cleaning processing liquid tank 30A, and stored. The cleaning liquid is pumped up by a processing liquid supply pump 33, and is supplied to a processing liquid inlet 2A of the upper and lower processing liquid nozzle blocks 2 and 3 via a supplied processing liquid conductivity detector 34 and a pressure gauge and / or a flow meter 35. , 3A, and is jetted from above and below the workpiece 11 along the wire electrode 1 to the processing portion. The detector 34 is controlled so that the conductivity of the cleaning fluid is maintained at a predetermined value. Is sent to a control device 40, which will be described later. When the conductivity exceeds a predetermined value, the controller 36 activates the pump 37 by a signal from the control device 40, pumps up the clean working fluid and causes the ion exchanger 38 to The conductivity is reduced by ion-exchange treatment and reflux to the cleaning processing liquid tank 30A, and the pump 37 is stopped at a predetermined value, and the processing liquid supply pump 33 and The controller 39 throttle or relief valve 33A is also placed under the control of a desired said control device so control is possible according to 40 is provided for.
[0021]
Reference numeral 40 denotes the above-described control device, which connects the Z-axis drive motor 12 of the processing head 7, the X and Y-axis drive motors 13 and 14 of the XY cross table 9, a UV table for taper processing (not shown) and a UV axis drive motor by wires. A numerical control device of 5-axis control for controlling a machining contour shape feed according to a programmed numerical control command and a feedback signal of the encoders 12A, 13A, 14A at the time of electric discharge machining, and the numerical control device and the controller 36; 39, and controls the operation so that various control signals corresponding to various detection input signals to the other controllers and operating bodies, various preset or programmed settings, and part programs are executed in a predetermined manner.
[0022]
FIG. 2 shows an example of the wire electrode automatic insertion mechanism 21. The wire electrode 1 sent down from the upper direction conversion pulley 20 is guided by a pair of die guide members 41 and is a pair of openable and closable rollers. When necessary, the wire electrode can be sent out and pulled back by pinching rotation of the wire electrode 1, and the wire electrode extends through the wire electrode clamp device 42 in the normally open state and extends to the distal end side. It is inserted into a thin guide pipe / working fluid injection pipe 43 of about the front and rear or less from a guide / water draining die 47 of a wire electrode insertion body 46 having a working fluid jet introduction block 44 and an introduction port 45 on the rear end side. It reaches the upper working fluid nozzle block 2. The wire electrode insertion body 46 is held by a rail 48 provided in the insertion mechanism 21 so as to be able to move up and down along the stretch axis of the wire electrode over substantially the entire length of the guide pipe 43. Controlled up and down movement and further positioning are performed by a belt 51 mounted on a pair of pulleys 49 and 50. FIG. 2 shows a state in which the insertion body 46 is at the highest position. A guide die 52 is provided at the end of the guide pipe 43 so as to be able to hang down with the guide pipe 43 inserted and positioned. At the outlet of 52, the tip processing of the wire electrode at the time of the first processing or after one or more automatic wire insertion failures, or the processing of the next part after the processing of one part is completed in the multi-cavity processing A cutting device 53 is provided for cutting the wire electrode, for example, for shifting, and the cutting operation of the wire electrode 1 is performed in a state where the tip of the guide pipe 43 is withdrawn from the guide die 52 and only the wire electrode is extended. Is what is done.
[0023]
42A is also used as the wire electrode feed roller There is A drive controller of the clamp device 42, 49A is a drive controller of the belt feed mechanism, and 53A is a drive controller of the cutting device 53. Although not shown, the guide pipe 43 is lowered, and in some cases, the guide pipe 43 is moved. When penetrating through the upper processing liquid nozzle block 2 and passing through the start hole 11A of the workpiece 11 and lowering it to the vicinity of a not-shown processing portion lower positioning guide in the lower processing liquid nozzle block 3 for inserting a wire electrode, It is necessary that the processing portion upper positioning guide 2B in the upper processing liquid nozzle block 2 be capable of opening and closing or changing the size of the guide hole by any configuration and operation. It is also necessary to perform an automatic evacuation operation such as passing an electric power of a wire electric discharge machining power supply to the wire electrode 1 provided in the block 2. And than, 2C is a driving controller for such positioning guide and the conducting member. 35A is a pressure and / or flow meter which may be the same as or the same as the pressure and / or flow meter 35 for sending the detection signal of FIG. 1 to the control device 40, and is a jet of the penetrating body 46 having the guide pipe 43. In the working fluid inlet 45 for Ueno When used in place of the buckle block 2, a pressure or flow meter 35B for detecting and measuring pressure or the like is provided in the same manner as described above.
[0024]
In the wire electrode automatic insertion device having the above-described configuration, the wire electrode 1 is usually fed with the jet of the working fluid in cooperation with the roller feed-out as needed, and the jet electrode of the guide pipe 43 of the insertion body 46 is usually used. However, depending on the configuration of the upper processing liquid nozzle block 2, a jet injection nozzle may be integrally formed inside the nozzle block 2, and in some cases, the nozzle 2N of the upper processing liquid nozzle block 2 may be used. May also serve as the guide pipe 43.
[0025]
In the above-described configuration, the workpiece 11 having one or more machining start holes 11A formed at predetermined dimensional positions of the workpiece 11 in the predetermined drawing is attached to the work stand 10 at a predetermined position or mounted. After the origin is determined by detecting contact between one or more predetermined end portions of the post-processed object 11 and the stretched wire electrode 1 or measuring by other appropriate measuring means, the wire electrode 1 is connected to the guide die 52 of FIG. At the exit, cutting is performed by the cutting device 53, and when the front wire electrode is collected in the wire collection box 27 by the feed roller 25, the guide pipe (working fluid injection tube) 43 and In order to match the center position of the upper processing liquid nozzle block 2 with the center position (coordinate position) of the processing start hole 11A of the workpiece 11, an X-axis and a Y-axis The upper working fluid nozzle block 2 is driven by the control device 40 to move the upper working fluid nozzle block 2 at a predetermined relative movement positioning position by a feedback signal from the encoders 13A and 14A, thereby driving the working head 7 to a predetermined proximity. If the inner diameter of the processing start hole 11A is sufficiently larger than the outer diameter of the guide pipe (machining liquid injection pipe) 43 by opening the positioning guide 2B in the nozzle block 2, the belt feed mechanism is opened. The controller 46A lowers the insertion body 46 to insert the guide pipe 43 into the start hole 11A so that the guide pipe 43 is preferably positioned just above the lower positioning guide (not shown) in the lower nozzle block 3. If the diameter of the guide pipe 43 is such that it is difficult to insert into the start hole 11A, the tip of the guide pipe 43 is The lower position is brought down to the extent that it is sufficiently close to or in contact with one surface, and a high-pressure working fluid for jet is introduced from the inlet 45 and jetted out of the guide pipe 43, or the jet jetting out of the upper working fluid nozzle block 2 is performed. Or if the wire electrode 1 is required, the tip is sent out to a predetermined position in the upper processing liquid nozzle block 2 using the clamp roller 42 as a feed-out roller, and the clamp roller 42 is sent out to the nozzle block 2 while performing jet jetting. Is rotated in the direction in which the wire electrode is sent out, and is operated so as to be inserted into the processing start hole 11A and the lower positioning guide, and to engage the wire electrode tip with the lower wire electrode take-off mechanism.
[0026]
However, the relative direct positioning between the guide pipe 43 and the processing start hole 11A and the indirect positioning such as the origin are not accurately performed, or the processing start hole 11A is not opened at a correct position. Or, if it is displaced by heat treatment or the like and has changed by a certain degree or more from the dimensional position in the drawing, the insertion purpose cannot be achieved by simply repeating the automatic insertion operation of the wire electrode, and the search for the machining start hole 11A and the actual This requires accurate measurement and positioning of the existing position.
[0027]
However, as in the above-described prior art, the tip of the wire electrode 1 is sent out and made to protrude from the upper working liquid nozzle block 2, and is contacted with the surface of the workpiece 11 not inserted into the start hole 11A, and separated from the start hole 11A. It is easy to presume that it would be difficult to accurately measure the center position, etc., and it is also necessary to use optical means that uses light or the like provided on the sides of the upper and lower working fluid nozzle blocks 2 and 3. In addition, it can be easily estimated that measurement is often difficult due to scattering and residue of the working fluid, various kinds of dirt, and the like.
[0028]
Therefore, according to the present invention, the machining fluid is ejected from the guide pipe (machining fluid ejection tube) 43 and / or the upper machining fluid nozzle block 2 which is conventionally used during wire electric discharge machining or automatic insertion of the wire electrode. Although the pressure is increased if necessary, the processing start hole 11A is searched and the position is measured using the pressure as it is.
[0029]
FIG. 3 illustrates a typical measurement principle in the present invention. Although FIG. 3 shows an example of the tip nozzle portion 2N of the upper working liquid nozzle block 2 in FIG. In the apparatus, a guide pipe (working fluid injection pipe) 43 is usually used.
In FIG. 3, FIG. 3A below shows a workpiece 11 placed on the work stand 10 so that the processing start hole 11A is not closed, and includes the center of the processing start hole 11A formed in the workpiece 11. A longitudinal section (XZ section) in a uniaxial (eg, X axis) direction, the start hole 11A projected on the XY plane, and the Y axis of the center of the opening of the nozzle 2N on the Y axis coordinate of the center of the start hole 11A. The workpiece 11 (start hole 11A) and the nozzle block 2 (nozzle 2N) are relatively moved and scanned in the X-axis direction on the Y-axis coordinates with the coordinates positioned. FIG. 3B shows the position of the nozzle 2N opening at a plurality of appropriate positions at the time when the nozzle 2N is pressed, the vertical axis represents the working fluid pressure (or flow rate) in the nozzle 2N, and the horizontal axis represents the nozzle 2N. Before the nozzle 2N As the position of the Y-axis coordinate on the in the X-axis direction, in which the relationship between the two described the status of the change in pressure (or flow rate) with respect to the position model basis. Note that k ₁ Is the working fluid pressure (or flow rate) in the working fluid supply pipe connected to the inside of the nozzle 2N with the front of the nozzle 2N opened, k ₂ In the state in which a disk-shaped nozzle is formed with the tip of the nozzle 2N being approximately 0.05 mm close to the flat surface of the workpiece 11, upper processing at the time of searching for a processing start hole 11A to be relatively moved and scanning and measuring the position. It is shown as a value approximating the processing liquid supply pressure (or flow rate) in the liquid nozzle block 2 or the supply pipeline to the liquid nozzle block.
[0030]
2N ₁ Is that the Y coordinate of the center of the nozzle 2N is on the same coordinate as the Y coordinate of the center of the processing start hole 11A of the workpiece 11 on the work stand 10, and the work stand 10 Since the working fluid is radiated from the nozzle 2N without any obstacle in a state of being separated from the surface of the nozzle 2N without any obstacle, the pressure in the nozzle 2N or its supply pipe is reduced to the low certain value k. ₁ , And the discharge flow rate is maximum. Then, by the relative scanning movement (movement in the X-axis direction on the Y-axis coordinate) for searching or measuring the processing start hole between the position or the processing liquid nozzle block 2 and the processing object 11, the opening of the nozzle 2N is changed. The controller 40 controls the drive of the Z-axis drive motor 12 or the drive controller 49A so that the distance between them becomes the above-mentioned fine distance of about 0.05 mm before they start to overlap with the end of the surface of the eleventh surface.
And this nozzle 2N ₁ From nozzle 2N ₂ During the scanning movement during the period, there is no change in the machining fluid ejection state by the nozzle 2N and the pressure k ₁ But the nozzle 2N ₂ And the pressure (or flow rate) is k until the openings of the nozzles 2N are all opposed to the surface of the workpiece 11 by the scanning movement. ₁ To k ₂ Until the pressure k rises (or decreases) in a generally gentle S-shaped curve. ₂ 2N at the leading edge of the processing start hole 11A ₃ Reach This nozzle 2N ₃ Position x ₁ Then, the nozzle 2N and the processing start hole 11A begin to overlap, and the pressure (or flow rate) of the processing liquid in the nozzle 2N is inversely proportional to the ratio of the diameter of the nozzle 2N to the diameter of the start hole 11A (however, when both diameters are 2N> 11A). The pressure drop in the relationship ₃ The pressure k decreases while drawing a small gentle inverted S-shaped curve until the apertures overlap. ₃ After the pressure is maintained, the pressure rises along a small loose S-shaped curve substantially opposite to that at the time of the pressure drop according to the separation of the two, and when the pressure is reduced, the separation position x ₂ And the pressure is k ₂ Until the pressure reaches the other end of the upper surface of the workpiece 11 in the X-axis direction. ₂ After that, the pressure (or flow rate) decreases (or increases) in a reverse S-shape as the workpiece 11 moves in the X-axis direction and moves away in the X-axis direction. ₄ Original k in position ₁ Will return to.
[0031]
If the scanning movement of the upper machining liquid nozzle block 2 with respect to the workpiece 11 and the machining start hole 11A in the above case is defined as a positive X-axis (or plus) movement, the position of the nozzle 2N in FIG. ₁ ~ 2N ₄ The state of the change in the pressure (or flow rate) with respect to the X-axis direction minus end and the plus direction end of the workpiece 11 and the position of the start hole 11A and the position in the X-axis direction in FIG. The nozzle 2N is displaced by the diameter of the nozzle 2N. ₄ Nozzle 2N from the position ₂ 3B, the characteristic curve of FIG. 3B is a characteristic curve displaced in the minus direction of the X-axis by the diameter of the nozzle 2N (twice the diameter in FIG. 3B). As a result, there is no problem in measuring the positional relationship between the nozzle 2N, the workpiece 11, and the start hole 11A and the pressure in the nozzle 2N or the working fluid supply pipe. Of course, the diameter of the processing start hole 11A may be smaller than the normal diameter of about 1 to 2 mmφ, and the pitch of the relative movement in the Y-axis direction may be reduced when the position of the start hole 11A is not known. Although it may be necessary to set the diameter of the hole 11A to at least about 1/3 or less for accurate measurement of the center of the diameter, the guide pipe 43 (a so-called automatic wire electrode) may be used instead of the nozzle 2N. If the insertion wire electrode guide and working liquid jet nozzle or pipe) is used, the diameter of the pipe 43 or the jet nozzle is about the same as the diameter of the processing start hole 11A, and it is often the case that the diameter is smaller in normal processing. 3A, the center Y coordinate of the diameter of the nozzle 2N coincides with the Y coordinate of the center of the start hole 11A during most of the initial scanning movement. Even if the state is small, it is possible to search for the position of the processing start hole 11A and measure it by measuring the change in the pressure (or flow rate) of the processing fluid in the nozzle 2N or its processing fluid supply pipe. it is obvious.
[0032]
4A to 4G show the position of the nozzle 2N during one scanning movement when performing the detection and measurement of the processing start hole 11A, the flow 2L of the discharge processing liquid, and the workpiece 11, And a relationship with the start hole 11A is shown in a side sectional view, where A is positioned at a measurement or scanning movement start position, and when the processing fluid 2L is started to be discharged from the nozzle 2N under predetermined measurement conditions, B is the above. At the position, the nozzle 2N is brought close to the above-mentioned predetermined value, for example, about 0.05 mm above the surface of the workpiece 11, and the nozzle 2N has a hydraulic pressure k in its supply pipe. ₂ (C) is a step of measuring the flow rate (or flow velocity) and starting a predetermined scanning movement. C is a state in which the scanning movement causes the front edge of the nozzle 2N in the scanning direction to approach the front edge of the start hole 11A in a predetermined state (for later measurement) D indicates a state in which the nozzle 2N and the start hole 11A are coaxially overlapped, and E indicates a state in which the trailing edge of the nozzle 2N deviates from the trailing edge of the start hole 11A in the scanning direction to a predetermined state. (It will be referred to as a second position in the subsequent measurement.), F is a state returned to the state substantially the same as B, G is at least up to F, and at least one axis on the XY plane or The figure shows a step in which the scanning movement in the two axial directions is completed, the nozzle 2N is separated from the surface of the workpiece 11 by a predetermined distance to stop the injection of the working fluid, and the scanning movement is completed.
[0033]
Thus, as a method of searching for the processing start hole 11A, the workpiece 11 is positioned and attached to the work stand 10 at a predetermined position, and the nozzle 2N is positioned at the mechanical origin or the origin of the desired position of the workpiece 11. ₁ After that, the laser beam is scanned or moved automatically or manually so as to scan and move the processing start hole 11A or the vicinity thereof, and the above-mentioned constant pressure (or flow rate) k ₂ Accordingly, when a decrease (or increase) in pressure (or flow rate) is detected and the start hole 11A is detected, a scan and calculation mode for measuring or determining the center position of the start hole 11A is preferably set, for example, by automatic switching setting or the like. Then, the scanning movement from, for example, the X axis with respect to the predetermined peripheral area of the start hole 11A detection position is started.
[0034]
As the measurement method in the scanning and calculation mode for measuring or determining the center position of the start hole 11A, at least three or more methods can be considered, respectively. Depending on conditions such as a detection characteristic of pressure (or flow rate) change with respect to a position in the scanning axis direction on the scanning pitch coordinate such as 3B, that is, in general, when detection and measurement are easy, etc. The configuration may be such that the scan and calculation mode for measurement is automatically switched from the scan and calculation mode for measurement to another scan and calculation mode for measurement capable of performing simpler or faster measurement.
[0035]
Note that the shift to the scan and calculation mode for measuring or determining the center position of the start hole 11A is performed because the numerical position of the start hole 11A on the workpiece 11 on the drawing is unknown and the start is performed. After the start hole search is detected in the hole search scanning mode, the workpiece 11 is positioned in accordance with a normal processing start procedure and the like, and further the start hole is positioned in accordance with figures in the drawing and the like, and the insertion operation of the wire electrode is performed. Before performing, or before the next re-insertion operation becomes practical after one or a predetermined number of unsuccessful insertion operations of the wire electrode, processing of a certain point is completed in the processing of multi-cavity or the like. Then, before performing the operation of inserting the start hole of the wire electrode for the processing of the next one place, or when the operation of inserting the wire electrode has failed once or a plurality of times, the process proceeds to the next re-insertion operation. It is a matter of course is before or the like.
[0036]
FIG. 5 shows a main configuration diagram of a control device 40 for executing a method of searching for a machining start hole 11A and measuring a hole position according to the present invention. Reference numeral 60 denotes a microprocessor such as a CPU; A storage device for storing programs and control programs and methods for the entire wire electric discharge machine, 62 is a RAM and the like, a temporary storage device for temporarily storing data and various setting values and calculation processing results, and 63 to 65 are usually A storage device for various programs which is constituted by a nonvolatile memory or the like and is additionally provided according to the present invention. R1 to R3 64, a desired or various arithmetic program storage device for calculating the center position of the start hole from the data measured and stored by scanning, and various later-described modes 1, 2, 3, etc .; and 65, a storage device 63 Scanning program R1 to R3 , And a control program storage device for reading the arithmetic programs (modes 1 to 3) in the storage device 64 and causing the CPU 60 to execute the position detection of the start hole of the present invention. Reference numeral 66 denotes external storage data such as a paper tape, a magnetic tape, or a disk. A manual data input device such as a keyboard; 68, a printer for printing input / output data; 69, a display device such as a CRT; 70, an NC interpolator 71-1 and upper working fluid nozzle block 2; A working fluid pressure (or flow rate) detector 70-n inside the working fluid supply line and other input / output circuits to which various input / outputs are connected. These are connected to the CPU 60 by a data and address bus 71. Have been.
[0037]
The scanning program stored in the storage device 63 by creating a program in advance is roughly divided into the following. R1 Or R3 Something like is prepared.
Scanning program R1 : This is also the most basic and simple scanning program. R1 When the execution command is input, the predetermined area on the XY plane where the nozzle 2N can be selected and switched from the state where the nozzle 2N is positioned close to the desired origin or the scanning start position specified by the designation input or the like is distorted in each axial direction. Scanning is sequentially performed, and during the scanning, for example, the position data and measured pressure (or flow rate) data are stored for each predetermined movement interval position, or one or a plurality of desired measured pressures (or flow rates) are stored. The value of the working fluid pressure (or flow rate) and its change required for calculating and determining the start hole 11A, which will be described later, such as storing position data increasing or decreasing from the value (for example, k2), and the working fluid. The data of the relative position of the injection pipe with respect to the workpiece 11 is stored in the temporary storage device 62.
[0038]
Scanning program R2 : This scanning program basically follows the above-mentioned scanning program I. During the scanning movement, for example, the measured pressure (or flow rate) is changed by the working fluid injection pipe, the start hole 11A and the workpiece 11 Select a certain degree of convenient relative position data by calculating or determining the position of the start hole 11A, for example, when the facing position shifts to a certain state or shifts from a certain state to another state. Alternatively, switching of the scanning movement path and pattern while discriminating is a scanning program configured to perform scanning movement while selecting and store data. For example, a search for a start hole illustrated in FIG. The flowchart of the detection and the center position detection measurement corresponds to an example, but is not limited to this.
[0039]
Scanning program R3 : This scanning program is also basically the same as the above-mentioned scanning program I, except that there are successive machining start holes 11Ai at or substantially at predetermined intervals on or near the path of the scanning movement. At the position where the next start hole 11Ai + 1 should be located or in the vicinity of the next start hole 11Ai + 1 in the course of further scanning following the scanning path. R1 Or R2 , The position data of the start hole 11Ai + 1 is detected and measured and stored, and then the scanning program is switched again to perform the scanning movement along the program path to the next start hole 11Ai + 2. The flowchart of the search and the center position detection measurement for a large number of start holes illustrated and described with reference to FIGS. 8A and 8B corresponds to an example, but is not limited thereto. Based on the relative relationship between the workpiece or the workpiece 11 and the working fluid injection pipe, detection of the start hole 11A and detection of the center position, detection and measurement of the center position, and detection and measurement of preferable position data are required. A possible scanning program is to be used.
[0040]
Then, based on the relative position data obtained by executing the scanning program as described above, the detection data of the relationship between the value of the pressure (or flow rate) and the relative position, or the storage data, the data is stored in the temporary storage device 62. Each time a readout or detection measurement is performed, a calculation program stored in a calculation program storage device 64 for performing the next scanning movement and finally calculating the center position of the start hole 11A. Are prepared for the following operation modes 1 to 3.
[0041]
(Calculation mode 1 of start hole center position measurement method)
A predetermined range around the detected processing start hole 11A is first defined in the Y-axis direction by the scanning program x in the storage device 63. Note Star Scanning movement in the X-axis direction plus / minus reciprocation at a predetermined pitch such as about 1/3 pitch of the hole diameter, or only in the direction from minus to plus, and then in the X-axis direction at the predetermined pitch in the Y-axis direction As in the case of the X-axis, the scanning is performed so that the two scans substantially overlap each other at right angles, and each scanning line has a position in the scanning axis direction as shown in FIG. 3B and the position at that position. The pressure of the working fluid or the value detected by the flow rate detector 35A (35B) is stored in the temporary storage device 62 as data, continuously or at predetermined position intervals, or as the position of a change point with respect to the predetermined value. Is read out after the above-described scanning movement or as appropriate, and the microprocessor 60 synthesizes and calculates as necessary according to a start hole center positioning calculation program (calculation mode 1) or the like, and displays the display device 6. It is for displaying together with the start hole 11A the center position of the coordinates.
[0042]
The calculation of the coordinates of the center position in the above case is performed by a number of known calculation methods, for example, the center position scanning axis of the nozzle 2N (y = C _i ) Overlaps the start hole 11A by a certain degree or more, the pressure becomes k ₂ From the point where it starts to fall, and the pressure k ₂ Are detected and measured, the coordinate values of the points that rise to the highest point on the scanning axis are detected by several straight lines (y = C _i ) And a circle of the start hole 11A having a known diameter ((xa) ² + (Y-b) ² = R ² ), Or the intersection of several straight lines connecting the pressure change point and the center of the nozzle 2N at that time, or the pressure (or flow rate) is k ₂ To k ₃ Pressure (or flow rate) k ₂ A method of drawing a known x-axis line and a y-axis line on the circle to determine the circle and its center from the intersection coordinates thereof, or drawing a diameter line where the x-axis line is the longest for the circle, A method of obtaining the center coordinate by drawing a diameter line of a known straight line intersecting the x-axis diameter line is appropriately adopted.
[0043]
(Calculation mode 2 of start hole center position measurement method)
In the first X-axis scanning movement, the center of the opening of the nozzle 2N and the center of the start hole 11A are located on the scanning movement axis, that is, the scanning movement is performed in the X-axis direction with the Y-axis coordinates coincident. Although it is preferable that the scanning movement in which the Y-axis coordinates coincide is rare, the opening movement of the nozzle 2N and the start hole 11A are more than a certain degree, and preferably close to half by the first X-axis scanning movement. In the overlapping scanning movement, first, the nozzle 2N of FIG. ₃ Starts to overlap the front edge of the start hole 11A, and the pressure becomes k ₂ Is detected as the first position on the X-axis which has started to fall from ₃ (The condition for the scanning movement is that the diameter of the nozzle 2N> the diameter of the start hole 11A, the latter has a scanning movement section within the former diameter, or the reverse of the above. Pressure k for conditions ₃ The x-coordinate which becomes constant and the pressure starts to rise again) or the scanning movement moves the nozzle 2N past the position of the start hole 11A, inverts the same Y-axis coordinate and moves the scanning in the minus direction of the X-axis. When the hour nozzle 2N starts to overlap with the leading edge of the start hole 11A on the plus side, the pressure becomes k ₂ The x coordinate starting to fall from a certain level is detected as the second position, the first and second positions are stored in the temporary storage device 62, and the stored data is input from the storage device 64 to the temporary storage device 62. When an intermediate x coordinate is obtained by the microprocessor 60 using an arithmetic program (operation mode 2) for the center position of the start hole, this is obtained as the x coordinate of the center of the start hole 11A.
[0044]
Therefore, after the scanning program II is executed by the above-described program (arithmetic mode 2) or further by the control program from the storage device 65, the center x coordinate of the nozzle 2N is made to coincide with the obtained center coordinate. The nozzle 2N, the workpiece 11, and the start hole 11A are relatively scanned and moved in the Y-axis direction, and the Y coordinate of the center of the start hole 11A is obtained in the same manner as in the X-axis direction scan movement.
[0045]
By doing so, it is possible to know the x and y coordinates of the center position of the start hole 11A, so that it can be stored, printed out or displayed, and further input from the reading device 66 or the input device 67. Correction of data and positioning of the nozzle 2N, the start hole 11A, and the workpiece 11 by relative movement with respect to the XY axes based on new data for automatic insertion of the wire electrode 1 are performed. After obtaining the axis coordinates, the scanning movement detection for confirming the x-axis coordinates may be repeated based on the y-axis coordinates.
[0046]
The method of obtaining the processing start hole 11A in the above is based on the position of the x or y coordinate of the leading edge or the trailing edge of the nozzle 2N when the nozzle 2N starts to overlap with the start hole 11A or when the nozzle 2N ends. And the second position, since the diameter of the nozzle 2N (of course, taking into account the thickness of its outer cover) is a known and unchanging one, the nozzle 2N is connected to the start hole 11A. The pressure (or flow rate) is k ₂ Nozzle 2N when it starts to fall from ₃ Is the first position, and the pressure (or the flow rate) at which the scanning movement is continued and the nozzle 2N ends to leave the start hole 11A is k. ₂ If the center position of the nozzle 2N at the time of ascending is detected and stored as the second position, the x coordinate of the center of the hole 11A on the scanning movement axis of the start hole 11A is determined by the first position. Is located halfway between the first position and the second position, and is not only easily obtained, but also, in the minus x direction, の of the distance that the nozzle 2N was moved from the first position to the second position. When returned, the position becomes the position of the x coordinate of the center of the hole 11A on the scanning movement axis of the start hole 11A.
[0047]
(Calculation mode 3 for start hole center position measurement method)
Due to one-way or reciprocal scanning movement on one scanning path in the X or Y axis direction, the pressure (or flow rate) on the X or Y axis on the scanning axis is k. ₂ Lower or k ₂ XY coordinates of one or two points that have finished ascending are detected, and then one of the scanning paths parallel to the scanning path and separated by at least one pitch, or one of the Y-axis or X-axis directions orthogonal to the detected scanning path. The pressure is k on the scanning axis due to the direction or reciprocal scanning movement. ₂ Pressure change from decreasing or increasing to k ₂ By detecting each xy coordinate of one or two points on the Y axis or the X axis, the coordinates of at least three points on one circle are stored in the temporary storage device 62, and the stored data is stored in the storage device. The center of the circle passing through the at least three points, that is, the coordinates of the center position of the start hole 11A is calculated by the microprocessor 60 by the calculation program (calculation mode 3) of the start hole center position input from the temporary storage device 62 from 64. Is what you want.
[0048]
FIG. 6 shows a scanning movement program I or II of the start hole center position measuring method for processing start hole 11A search and / or start hole 11A located in a predetermined area near the current position, and start hole center. In the flowchart of the search or scanning movement and the calculation by the calculation program of the center position in the calculation mode 2 of the position measuring method, the scanning program is started, and the nozzle is moved to the work piece 11 which is fixed to the work stand 10 at a predetermined position in step S1. The center of 2N is stored at a predetermined mechanical origin or a position where there is no start hole 11A moved a desired distance from a predetermined reference position of the workpiece 11, and the nozzle 2N (or the guide pipe 43) is driven by the Z-axis motor 12 or the controller 49A. Move the workpiece to the surface of the workpiece 11 and position it close to it. To start the injection to the state of looking 1A.
[0049]
Next, in step S2, a numerical control unit instructs the scanning moving device (the work table 11 mounting table 9 and its XY-axis driving device in FIG. 1) at a predetermined pitch according to the scanning program, for example, from the X-axis direction. The scanning movement is started. At this time, the scanning movement in the X-axis direction on the Y-axis coordinate by the encoder 14A is performed by the pressure and / or flow meter 35A (or 35B) in the nozzle 2N (or the guide pipe 43) or its supply path. The pressure (or flow rate) change is stored for each desired position interval, and when there is a change, the position and the value of the changed pressure (or flow rate) are stored in the temporary storage device 62 as data, and It is determined whether there has been a change in pressure (or flow rate) greater than or equal to a predetermined value at the time of the scanning movement at every one pitch or one reciprocating scanning movement or during the scanning movement. (Step S3) If there is no change or less than the certain predetermined value, the nozzle 2N (guide pipe 43) and the start hole 11A still cross the predetermined state and do not overlap. Returning to step S2, the scanning movement at the next Y-axis pitch is continued. If a change in pressure (or flow rate) equal to or more than a predetermined value is detected, for example, the center of the start hole 11A as shown in FIG. The process proceeds to the position measurement scanning program II.
[0050]
That is, in step S4, the nozzle 2N of FIG. ₃ After detecting and storing the position of (or the guide pipe 43) as the first pressure change position by the encoder 13A, the scanning movement is continued, and when the same pressure change state opposite to the first position is detected, The position is detected and stored by the encoder 13A as the second position (step S5), and the microprocessor 60 calculates the center x-axis position of the nozzle 2N (or the guide pipe 43) at the point of the first position and the second position. The x-coordinate position of the center of the center x-axis coordinate of the nozzle 2N (or the guide pipe 43) at the position point is regarded as the x-coordinate of the center of the start hole 11A, and the nozzle 2N (or the guide pipe 43) is used as the workpiece 11 Relative to the first position and the second position, the nozzle 2N (or the guide pipe 43) is moved so as to coincide with the center position (step S). ).
[0051]
In this case, the intermediate position between the first and second positions is not only obtained by calculation or the like as the above-mentioned x coordinate value, but also during movement from the first position to the second position. Various calculation methods such as measuring the distance (distance) by measuring the known scanning movement speed and movement time, or taking the product of the known movement setting unit and the count value of the command signal executed by the numerical controller for performing the scanning movement. Is adopted.
[0052]
The next step S7 is to shift to the stage of the scanning movement of the Y axis orthogonal to the X axis of the scanning movement described above. First, the nozzle 2N (or the guide pipe 43) is moved in the Y axis direction on the x coordinate. After once moving relatively to a preset distance, that is, a position outside the start hole 11A of the workpiece 11, the process moves to the scanning movement process in the Y-axis direction (Step S8) similar to Step S2 described above. is there. Since this step S8 is the scanning movement in the Y-axis direction on the x-coordinate obtained as described above, the first step in the Y-axis direction similar to step S4 without the step S3 is required. After the process proceeds to the pressure change position detection step (step S9), and after the same second pressure change position detection step (step S10), the Y-axis direction center y coordinate of the start hole 11A may be obtained in the same manner as in step S6. In addition, in preparation for the next transition to the wire electrode insertion process, the length is returned in the Y-axis direction by a half of the length moved from the first position in step 9 to the second position in step 10. Then, the measurement position of the encoder 14A at that time is the y coordinate which is the center in the Y axis direction.
[0053]
As described above, since the detection and measurement of the center position of the start hole 11A has been completed here, the detected and measured data can be used as a command signal of, for example, a numerical controller for automatic insertion of a wire electrode, or further display of data. Then, the storage and storage processing (step 11) is performed, and the processing ends. If necessary, the scanning program can be configured to perform the detection measurement twice or more in order to increase the accuracy of the detection measurement of the center position of a certain processing start hole 11A as described above (step S12). Alternatively, at this time, the configuration may be such that the detection measurement is terminated when the error between the two detection measurement values is within a predetermined allowable limit value (step S13).
[0054]
FIG. 7 shows that the guide pipe 43 is used during the automatic insertion operation of the wire electrode 1 as described above, and the upper positioning guide 2B is used when the outer diameter of the guide pipe 43 is smaller than the inner diameter of the start hole 11A. When the guide electrode 43 is inserted into the start hole 11A by opening and closing, and the wire electrode is inserted into the lower positioning guide of the lower nozzle block 3 by the jetting of the machining liquid, the insertion of the wire electrode fails. In the re-insertion operation, there is shown a schematic flowchart in which the position detection processing step of the start hole 11A in FIG. 6 is introduced to increase the insertion success accuracy. At the stage when the insertion operation has failed, in the case of FIGS. 1 and 2 described above, the guide electrode 43 is pulled up to the position of FIG. The wire electrode 1 on the workpiece 11 is removed by winding or other appropriate means, and the wire electrode 1 is removed by the clamp device 42 behind the guide pipe 43 during this cutting (step S21). The clamping is performed (step S22). Next, in order to correct the positioning of the nozzle 2N (or the guide pipe 43), which is considered to be the cause of the failure in moving and inserting the wire electrode, and the start hole 11A of the workpiece 11, FIG. The process moves to step S23 consisting of steps S1 to S11 or S1 to S13.
[0055]
In this case, since the automatic insertion operation of the wire electrode 1 has failed at least once, the operation of detecting the position of the start hole 11A in FIG. 6 is performed precisely, and therefore preferably performed two or more times. Is preferred.
[0056]
Next, as described above, when the outer diameter of the guide pipe 43 is smaller than the inner diameter of the start hole 11A, the wire guide 2B in the upper nozzle block 2 is opened so that the pipe can be inserted. The guide pipe 43 is driven by the drive rollers 49 and 50 and the belt 51 by appropriately retreating the electron-transmitting member and the pressing body, etc., so as to drive the upper nozzle block 2 from the upper nozzle block 2 through the start hole 11A and immediately before the lower positioning guide in the lower nozzle block 3. It is lowered to the position (step S24). As will be described later, the wire electrode 1 is slightly rewound as required when the automatic insertion operation fails, for example, and the wire electrode 1 is slackened at an appropriate position between the tension roller 18 and the automatic wire electrode setting device 21, for example. In this case (step S25), a predetermined amount of the wire electrode is pulled out of the bobbin 15 using, for example, a tension roller 18 or the like, and preferably the wire electrode is inserted between the upper direction changing pulley 20 and the automatic setting device 21 or the like. A working fluid is supplied to the guide pipe 43 in a state where a predetermined amount of 1 has been stored (step S26) and jetted, the pair of clamp devices 42 are separated, and the tip of the wire electrode 1 is sent out by releasing the clamp (step 27).
[0057]
If the tip of the wire electrode 1 is confirmed from the downward conversion pulley 22 by the insertion success confirmation means provided in the guide pipe 23, the wire electrode take-up device 25, or the wire collection box 27 (step S28), the wire electrode is detected. The automatic insertion operation is completed, and the process proceeds to the next wire electric discharge machining start step or the like. If the insertion success confirmation signal is not obtained, the guide pipe 43 is pulled up from the step S28 and the wire electrode is moved by a predetermined amount. Rewinding (step S29) returns to step S21 of cutting the wire electrode tip. Note that, when the operation is shifted to the processing after the operation shown in the flowchart of FIG. 7, since the processing start point of the processing shape program input in advance and the wire electrode insertion position newly determined and determined are shifted. In some cases, it may be impossible to start machining as it is. In this case, the movement connecting the newly determined wire electrode insertion position and the machining start point of the desired machining shape program depends on the wire electrode insertion position and the machining. By moving in the machining mode between the start points of the program in the machining mode, or by connecting in the machining mode when contact between the wire electrode and the workpiece is detected during the movement, machining can be executed without any problem even if the positional deviation is large.
[0058]
8A and 8B show a large number of start holes 11A as shown in FIG. ₁ 8B illustrates an example of FIG. 8B, in which the number of the workpieces 11 is set at the center of the nozzle 2N (or the guide pipe 43). Hole 11A ₁ Starting point 2N related to position detection of .about.n ₀ To start the machining liquid jet (step S30). Next, the nozzle 2N (or the guide pipe 43) is positioned close to the surface of the workpiece 11 by driving the Z-axis drive motor 12 (or the controller 49A), and the processing liquid in the nozzle 2N (or the guide pipe 43) or its supply path. (Step S31), and when a predetermined state is reached, the large number of start holes 11A ₁ The execution of a scanning movement program III for sequentially searching for a predetermined route n through a predetermined programmed route SL is started (step S32). If a change in the working fluid pressure in the nozzle 2N (or the guide pipe 43) or in the supply path is detected during the scanning movement of the path SL following the forward path (step S33), the first or predetermined i-th processing start hole is formed. 11A ₁ (Or 11A _i ), The process proceeds to the execution stage (step S34) of steps S2 to S11 of the scanning movement program II in FIG. 6, for example, and the detection start hole 11A is detected. ₁ (Or 11A _i The position coordinates are detected and measured.
[0059]
Then, start hole 11A ₁ (Or 11A _i )), The process proceeds to a step of determining whether or not to perform wire electric discharge machining by automatically inserting the wire electrode 1 (step S35). In the case of setting to perform machining, the process proceeds to step S36A of the next machining execution. If not, the start hole 11A where the above detection and measurement were performed ₁ (Or 11A _i ) Is stored in the storage device with the coordinates of the first (or i-th) start hole and the measurement center position thereof (step S36B), and the process proceeds to the end determination step (step S37) of the next scanning movement program III, and ends. If not, the flow returns to step S32 to resume the execution of the scanning program III, and the next machining start hole 11A is made in accordance with the trajectory of the programmed scanning movement. ₂ (Or 11A _{i + 1} ), And then the above-mentioned scanning movement program III ends, and the nozzle 2N (or the guide pipe 43) moves to the end position 2N of the scanning movement program III. _n Is repeated until it reaches.
[0060]
The present invention has been described with reference to the illustrated embodiment. However, in the case where the diameter of the machining start hole 11A is extremely small with respect to the diameter of the nozzle 2N of the upper nozzle block 2, there is a difference as described above. In addition to using the guide pipe 43 having a normally small diameter as described above, the nozzle 2N can be replaced with a nozzle 2N having an appropriate size and shape for detection and measurement, as well as the nozzle 2N and the guide. In place of the pipe 43, a nozzle for detection and measurement may be provided, for example, at the tip end of the nozzle 2N so as to be able to advance and retract. The pressure or flow rate of the working fluid in the nozzle 2N (or the guide pipe 43) or in the working fluid flow path connected to the nozzle 2N (or the guide pipe 43) depends on the diameter of the nozzle 2N (or the guide pipe 43), the diameter of the start hole 11A, or the ratio thereof. It is preferable to make it easy to detect and measure the state of pressure or flow rate change as described above, so that the processing fluid supplied to the nozzle 2N (or the guide pipe 43) when detecting the processing start hole 11A and measuring the position, etc. As the supply means, a machining fluid supply means different from the machining fluid supply means used at the time of wire electric discharge machining illustrated and described above may be provided completely separately or attached to the machining fluid circulating supply device 30, As the device 35, 35A or 35B for detecting the pressure or flow rate of the working fluid in the nozzle 2N or the guide pipe 43 or in the supply path thereof, a known pressure gauge such as a metal resistor or a semiconductor element Strain gauges, capacitance and inductance type displacement sensors, differential transformers, etc. Also known flow meters (flow meters), squeeze flow meters, area flow meters, electromagnetic flow meters, vortex flow sensors, ultrasonic and thermal linear It is possible to use a flow rate sensor or a turbine type flow rate sensor, etc. Also, the mode of automatic insertion operation of the wire electrode after the detection of the processing start hole 11A by the nozzle 2N or the guide pipe 43 and the position measurement are described above. It is a matter of course that the present invention is not limited to this. In the embodiment of the present invention, the method and the apparatus for detecting the pressure change or the flow rate change by injecting the working fluid from the nozzle 2N or the guide pipe 43 to the workpiece 11 have been described. In the case of the immersion type wire electric discharge machine, Is provided with a suction device in place of the configuration for supplying the pressurized working fluid to the nozzle 2N and the guide pipe 43, and detects and measures changes in the amount of working fluid flowing from the nozzle 2N and the guide pipe 43 and changes in suction negative pressure. It can also be.
[0061]
【The invention's effect】
As described in detail above, according to the method and the apparatus for detecting the position of the processing start hole according to the present invention,
The machining liquid jet nozzle provided on the upper machining head There is A processing fluid injection pipe facing vertically below the workpiece to be processed, and forming at least one processing start hole formed in a desired position of the workpiece in advance in a direction perpendicular to the facing direction. To search by relative feed of control command,
A step of starting the injection of the machining fluid by bringing the machining fluid injection pipe close to a predetermined state on the upper surface of the workpiece and starting the measurement of the pressure or the flow rate of the machining fluid in the injection pipe or a flow path connected thereto; When,
Scanning the working fluid injection pipe relative to the workpiece in a predetermined area in a direction perpendicular to the facing direction relative to the workpiece by a preset scanning program in a predetermined order,
A step of measuring and storing relational data of a relative position by scanning of the relative movement with respect to a change in pressure or flow rate of the working fluid in the working fluid injection pipe or a flow path connected thereto,
Calculate based on the stored data of the relationship between the change in the pressure or flow rate of the machining fluid in the machining fluid injection pipe or the flow path connected thereto and the relative position between the machining fluid injection pipe and the workpiece and the machining fluid injection pipe. Determining a relative position to the start hole,
[0062]
By determining the center position of the start hole as the center or the like between two points where the change state of pressure or the like in each of the axial directions orthogonal to the right angle direction is determined, the center position coordinates can be determined. If the position of the hole is known from the failure of the automatic insertion of the wire electrode or from the drawing data, etc., the hole can be detected and measured from the start hole search and detection stage. Conventionally, such a wire electric discharge machine is equipped with a machining liquid jet nozzle such as a machining fluid jet nozzle for wire electric discharge machining or a machining fluid jet jet guide pipe for moving and inserting a wire electrode. , Which has the advantage that it can be performed without being disturbed by dirt etc.
[0063]
According to the wire electrode automatic insertion method and device of the present invention,
The machining liquid jet nozzle provided on the upper machining head There is A wire electrode is inserted through a working fluid injection pipe, and the working fluid injection pipe is opposed to a workpiece disposed vertically below, and one or more workpieces formed in advance at desired positions on the workpiece. After positioning by machining relative to the machining start hole and the numerical control command in the direction perpendicular to the facing direction, when the wire electrode is sent out from the machining fluid injection pipe and inserted into the start hole, or once to the start hole. At the time of the reinsertion operation after the failure detection of the above insertion operation,
Holding the wire electrode at the rear end of the injection tube with the tip of the wire electrode being inserted from the rear end of the working fluid injection tube at a predetermined position, and clamping the wire electrode at the rear end of the injection tube,
The injection of the machining fluid is started by bringing the machining fluid injection pipe close to a predetermined state on the upper surface of the workpiece, and the measurement of the pressure or the flow rate of the machining fluid in or in the flow path in or connected to the machining fluid injection pipe is performed. To start,
Scanning the working fluid injection pipe relative to the workpiece in a predetermined area in a direction perpendicular to the facing direction relative to the workpiece by a preset scanning program in a predetermined order,
A step of measuring and storing relational data of a relative position by scanning of the relative movement with respect to a change in pressure or flow rate of the working fluid in the working fluid injection pipe or a flow path connected thereto,
Calculate based on the stored data of the relationship between the change in the pressure or flow rate of the machining fluid in the machining fluid injection pipe or the flow path connected thereto and the relative position between the machining fluid injection pipe and the workpiece and the machining fluid injection pipe. Determining a relative position to the start hole;
Performing relative feed in the direction perpendicular to the facing direction according to the newly determined relative position data and relatively positioning the working fluid injection pipe and the start hole;
Releasing the clamping clamp of the wire electrode and increasing the working fluid supply pressure to the working fluid injection tube.
[0064]
Prior to the operation of searching for the processing start hole and detecting the center position of the hole, the wire electrode is gripped and clamped at the rear end of the rear end with the front end of the wire electrode inserted for a predetermined length from the rear end side of the working fluid injection tube. Therefore, after the above-described detection and measurement of the center position of the processing start hole, even if two or three other preparation operations are required, the center of the processing liquid injection pipe is made to coincide with the center of the start hole. Since the wire electrode automatic insertion operation is performed by releasing the liquid jet injection and the clamping of the wire electrode, the automatic wire insertion operation can be performed quickly and reliably.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a schematic configuration of an entire apparatus for performing a method of the present invention.
FIG. 2 is an explanatory front view showing a configuration of a main part of FIG. 1;
FIGS. 3A and 3B are explanatory diagrams showing the relationship between the relative positions of a nozzle, a workpiece, and a start hole for performing hole detection and position detection measurement of the present invention, and pressure changes.
4A to 4G are schematic flow diagrams showing FIG. 3A by a side sectional view of a part.
FIG. 5 is an explanatory diagram of a main configuration of a control device that implements the method of the present invention.
FIG. 6 is an explanatory flowchart of search and detection of a star and a hole and measurement of center position detection according to the present invention.
FIG. 7 is an explanatory flowchart in the case of detecting the center position of a star and a hole and subsequently performing an automatic wire electrode insertion operation of the present invention.
FIG. 8 is an explanatory flowchart in the case where the search for the start hole and the measurement of the center position detection according to the present invention are applied to a workpiece having a large number of stars and holes.
[Explanation of symbols]
1 wire electrode
2,3 upper and lower working fluid nozzle block
2A, 2B machining fluid inlet
4 base beds
5 columns
6,8 Upper and lower arm
7 Processing head
9 XY cross table
10 Workstand
11 Workpiece
11A Processing start hole
12,13,14 Z, X, Y axis drive motor
12A, 13A, 14A Each axis encoder
15 Wire electrode supply bobbin
16 Guide roller
17 Information
18 tension roller
19 Pinch roller
20,22 Upper and lower direction change pulley
21 Wire electrode automatic insertion mechanism
23 Guide pipe
24 Suction device
25 Wire feed roller
26 Wire electrode discharge section
27 Wire electrode collection box
28 Purification roller
29 Disconnection detector
30 Processing fluid supply device
30A, 30B Clean, dirty processing liquid tank
31, 33, 37 pump
32 filter
34 Conductivity detector
35, 35A, 35B Pressure gauge (flow meter)
36, 39 Controller
38 Ion exchanger
40 control device
41 Dice guide member
42 Wire electrode clamp device
43 Guide pipe and machining liquid injection pipe
44 Introduction block
45 Inlet
46 Wire electrode insert
47 Drainer dice
48 rails
49,50 pulley
51 belt
52 Guide dice
53 Cutting device
42A, 49A, 53A, 2C drive controller
60 Microprocessor (CPU)
61 Storage device (ROM)
62 Temporary storage device (RAM)
63, 64, 65 program storage device
66 Reading device
67 Manual input device
68 Printer
69 display device
70 I / O device
71 Data and Address Bus

Claims (8)

At a method of detecting the position of the start hole formed in the workpiece in the wire electric discharge machining, machining liquid injection nozzle vertically below the combined child Togaa Ru machining solution jetting pipe provided in the upper machining head In order to search for one or more machining start holes formed at a desired position of the workpiece in advance at a desired position on the workpiece by relative feed of a numerical control command in a direction perpendicular to the facing direction. Then, the processing fluid injection pipe is brought close to a predetermined state on the upper surface of the workpiece to start injection of the processing liquid, and measurement of the pressure or flow rate of the processing liquid in the injection pipe or the flow path connected thereto is started. Scanning a working fluid injection pipe relative to the workpiece in a predetermined order in a direction perpendicular to the facing direction in a predetermined order relative to the workpiece by a preset scanning program; Inside the machining fluid injection pipe Measuring and storing the relative data of the relative position by scanning the relative movement with respect to the change in the pressure or flow rate of the working fluid in the flow path connected to the working fluid, and the pressure or Calculating the relative position between the machining fluid injection tube and the start hole by calculating based on the stored data of the relationship between the change in the flow rate and the relative position between the machining fluid injection tube and the workpiece. Method for detecting the position of the start hole in wire electric discharge machining. At a method of detecting the position of the start hole formed in the workpiece in the wire electric discharge machining, a machining liquid injection nozzle wire electrode to the machining solution jetting pipe Ru combined child Togaa provided in the upper machining head The processing fluid injection pipe is inserted into the processing object, and the processing liquid injection pipe is opposed to a processing object disposed vertically downward, and one or more processing start holes formed in advance at desired positions of the processing object are perpendicular to the facing direction. After positioning by relative feed of a numerical control command in the direction, when the wire electrode is sent out from the machining fluid injection pipe and inserted into the start hole, or when one or more wire electrode insertion operations into the start hole fail. At the time of the re-insertion operation after the detection, the working fluid injection pipe is brought close to a predetermined state on the upper surface of the workpiece to start the injection of the working fluid, and the inside of the working fluid injection pipe is connected to the flow path connected thereto. Measurement of machining fluid pressure or flow rate Starting and scanning the working fluid injection tube relative to the workpiece in a predetermined area in a direction perpendicular to the facing direction relative to the workpiece by a preset scanning program in a predetermined order. Measuring and storing data on the relative position of the relative movement by scanning of the relative movement with respect to the change in the pressure or flow rate of the machining fluid in or in the machining fluid injection pipe, and the flow in or in the machining fluid injection pipe. Determining the relative position between the machining fluid injection pipe and the start hole by calculating based on the stored data of the relationship between the change in the pressure or flow rate of the machining fluid in the path and the relative position between the machining fluid injection pipe and the workpiece And a method for detecting the position of a start hole in wire electric discharge machining. The relative scanning movement in the direction perpendicular to the facing direction according to the setting scanning program between the workpiece and the working fluid injection pipe, and the pressure or flow rate of the working fluid in the working fluid injection pipe or the flow path connected to the same at that time. The data to be measured and stored in relation to the relative position by the scanning of the movement and the determination of the relative position between the working fluid injection pipe and the start hole calculated based on the stored data include the following steps (a) to (f). 3. The method for detecting a position of a start hole in wire electric discharge machining according to claim 1, wherein the method is performed in a subsequent step.
(A) executing the scanning as reciprocating at a predetermined pitch in one axis direction and reciprocating a predetermined set distance in another axis direction perpendicular to the one axis direction; and (b) performing the processing by the scanning movement. a liquid injection pipe and the start hole at a scan route overlapping predetermined ratio or more, the tube opening and the hole opening and the pressure or flow rate measurement of the working fluid the position of the predetermined value began to increase overlap more than a predetermined value (C) scanning movement after the step (b), which directly or indirectly stores the first position data due to the change, and thereby the overlap between the pipe port and the hole port starts to decrease, and Storing the overlapping position equivalent to the position 1 as the second position data directly or indirectly by a change in the measured value of the pressure or flow rate of the working fluid; and (d) storing the first position and the second position. From the stored data of the position, Calculating the intermediate position of the search path by calculating, and (e) starting the scanning movement by switching to the scanning movement in the one axis direction perpendicular to the scanning movement axis in accordance with the coordinates of the intermediate position on the scanning movement axis. And (f) performing the steps (b), (c) and (d) in the scanning movement of the other axis in the scanning movement in the one axis direction in order, and Finding the position. A working fluid injection tube working fluid ejection nozzle provided in the upper machining head which is held in close proximity and separable positionable in the machine body from above Ru combined child Togaa to workpiece installed in the processing table, the processing A machining fluid supply device for ejecting machining fluid from the ejection pipe in a state where the liquid ejection pipe is positioned close to the upper surface of the workpiece, and a machining fluid supply pipe provided on the machining fluid ejection pipe or a machining fluid supply pipe connected to the same. The apparatus stores a device for measuring the pressure or flow rate of the machining fluid in a portion, and a scanning program for scanning and moving the machining fluid injection tube relatively in the direction perpendicular to the direction facing the workpiece at the close position. A scanning program storage device, a relative movement scanning device for executing the storage scanning program of the scanning program storage device under the control of a numerical controller, and a relative movement scanning device between the working fluid ejection tube and the workpiece; Execution of the scanning program, at the time of moving scanning, a storage device for sequentially storing relational data of the coordinate position of the moving scanning with respect to the measured value of the pressure or flow rate of the machining fluid by the measuring device, and a predetermined moving scan of the moving scanning device. After completion, the stored data of the relationship between the pressure or flow rate of the measured processing fluid and the relative position between the processing fluid injection pipe and the workpiece is read from the storage device, and the relative position between the processing liquid injection pipe and the processing start hole is calculated. And a numerical value for controlling the operation of the machining fluid supply device, the machining fluid pressure or flow rate measuring device, the moving scanning device, the scanning program and data storage devices, and the operation of the arithmetic program storage device. A start hole position detecting device in wire electric discharge machining, comprising a control device having a control device. In the method of automatically inserting a wire electrode into the machining start hole in wire electric discharge machining,
The wire electrode is inserted in the machining solution jetting pipe working fluid ejection nozzle is Ru combined child Togaa provided in the upper machining head, allowed the workpiece and opposite arranged the working fluid injection tube vertically downwards, the After positioning by relative feed of one or more processing start holes formed in advance at desired positions of the workpiece and numerical control commands in a direction perpendicular to the facing direction, the wire electrode is sent out from the working fluid injection pipe. At the time of insertion into the start hole, or at the time of re-insertion operation after detecting failure of one or more wire electrode insertion operation into the start hole,
Holding the wire electrode at the rear end of the injection tube with the tip of the wire electrode being inserted from the rear end of the working fluid injection tube at a predetermined position, and clamping the wire electrode at the rear end of the injection tube,
The injection of the machining fluid is started by bringing the machining fluid injection pipe close to a predetermined state on the upper surface of the workpiece, and the measurement of the pressure or the flow rate of the machining fluid in or in the flow path in or connected to the machining fluid injection pipe is performed. To start,
Scanning the working fluid injection pipe relative to the workpiece in a predetermined area in a direction perpendicular to the facing direction relative to the workpiece by a preset scanning program in a predetermined order,
A step of measuring and storing relational data of a relative position by scanning of the relative movement with respect to a change in pressure or flow rate of the working fluid in the working fluid injection pipe or a flow path connected thereto,
Calculate based on the stored data of the relationship between the change in the pressure or flow rate of the machining fluid in the machining fluid injection pipe or the flow path connected thereto and the relative position between the machining fluid injection pipe and the workpiece and the machining fluid injection pipe. Determining a relative position to the start hole;
Performing relative feed in the direction perpendicular to the facing direction according to the newly determined relative position data and relatively positioning the working fluid injection pipe and the start hole;
Releasing the grip clamp of the wire electrode and increasing the working fluid supply pressure to the working fluid injection pipe,
A method for automatically inserting a wire electrode into a machining start hole in wire electric discharge machining, characterized by having: Relative scanning movement in the direction perpendicular to the facing direction by the setting program between the workpiece and the working fluid injection pipe, and the relative movement of the pressure or flow rate of the working fluid in the working fluid injection pipe or the flow path connected thereto at that time. The data stored in relation to the relative position by the scanning and the determination of the relative position between the machining fluid injection pipe and the start hole calculated based on the stored data are performed in the following steps (a) to (f). And
According to the relative position data newly determined through the step (f), the relative feed in the direction perpendicular to the facing direction is performed to perform the relative positioning between the working fluid injection tube and the start hole, and then the gripping clamp of the wire electrode is performed. 6. The method for automatically inserting a wire electrode into a start hole in wire electric discharge machining according to claim 5, further comprising the step of inserting a wire electrode to cancel the pressure and increase the supply pressure of the machining fluid to the machining fluid injection pipe. .
(A) executing the scanning as a reciprocating scan at a predetermined pitch in one axis direction and a predetermined set distance in the other axis direction perpendicular to the one axis direction;
(B) In a scanning path in which the machining fluid injection tube and the start hole overlap by a predetermined ratio or more by the scanning movement, the position of the predetermined value at which the pipe port and the hole port overlap and start to increase by the predetermined value is determined. Storing as a direct or indirect first position data by a measured value change of the pressure or flow rate of the working fluid;
(C) By the scanning movement after the step (b), the overlap between the pipe port and the hole starts to decrease, and the overlap position equivalent to the first position is a measured value of the pressure or flow rate of the working fluid. Storing as a direct or indirect second position data by the change;
(D) calculating and calculating an intermediate position between the scanning paths at both positions from the stored data at the first position and the second position;
(E) starting the scanning movement by switching to the scanning movement in the one axis direction perpendicular to the scanning movement axis according to the coordinates of the intermediate position on the scanning movement axis;
(F) In the scanning movement in the one axis direction, the above-mentioned steps (b), (c) and (d) in the relative movement of the other axis are sequentially executed to determine the center position of the start hole. Seeking stage. And the machining fluid ejection nozzle provided in the upper machining head which is held in close proximity and separable positionable in the machine body from above combined child Togaa Ru machining liquid injection pipe to the workpiece which is placed on the processing table,
In a state in which the tip of the wire electrode is inserted in a predetermined manner from the rear end of the machining liquid injection tube, a clamp device which is always in an open state to grip and clamp the wire electrode at the rear end of the rear end of the injection tube,
A machining liquid supply device that ejects machining fluid from the ejection pipe in a state where the machining liquid ejection pipe is positioned close to the upper surface of the workpiece,
A device for measuring the pressure or flow rate of the machining fluid in the portion provided in the machining fluid injection pipe or the machining fluid supply conduit connected to the same,
A scanning program storage device that stores a scanning program for relatively moving the machining fluid injection tube in the direction perpendicular to the direction facing the workpiece at the close position,
A relative movement scanning device between the machining liquid injection tube and the workpiece to execute a storage scanning program of the scanning program storage device under control by a numerical controller;
Execution of the scanning program by the moving scanning device at the time of moving scanning, a storage device for sequentially storing relational data of the coordinate position of the moving scan with respect to the measurement value of the pressure or flow rate measuring device of the working fluid,
After the end of the predetermined moving scan by the moving scanning device, the stored data of the relationship between the pressure or flow rate of the measured working fluid and the relative position between the working fluid ejection tube and the workpiece is read out from the storage device, and the machining fluid ejection tube is read. A calculation program storage device for calculating and determining the relative position with respect to the machining start hole,
In accordance with the relative position data newly determined by the above calculation result, a relative movement command signal in a direction perpendicular to the facing direction is given to the moving scanning device to cause the positioning of the working fluid injection pipe and the start hole, and then the clamp device is instructed. A wire electrode insertion command device that supplies a signal to release the clamp and outputs a supply working fluid pressure increase command signal to the working fluid supply device,
Numerical values for controlling the operations of the clamp device, the working fluid supply device, the working fluid pressure or flow rate measuring device, the moving scanning device, the respective storage devices for the scanning program and data, the operation program storage device, and the wire electrode insertion command device. An automatic wire electrode inserting device into a machining start hole in wire electric discharge machining, comprising: a control device having a control device. In a start hole searching method for searching for the position of a start hole provided in a workpiece prior to processing ,
A step of facing a measurement member that sprays a processing liquid provided on the upper processing head to the upper surface of the workpiece at a predetermined distance,
The step of relatively horizontally scanning and moving the upper surface of the workpiece while spraying the machining fluid from the measurement member,
Detecting a change in pressure (or flow rate) of the processing liquid supplied to the measurement member during the scanning movement in relation to a scanning position;
Calculating a start hole position from the scanning position data that has detected the change in pressure (or flow rate).

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